Electrochemical behaviour of gamma hydroxybutyric acid at a platinum electrode in acidic medium

Abstract

Abstract.Gamma Hydroxybutyric Acid (GHB), when studied in a platinum electrode using cyclic voltammetry, presented three oxidation peaks in acid solutions that correspond to the oxidation of the alcohol group to the corresponding aldehyde and carboxylic acid (succinic acid). An anodic scan of GHB yielded two characteristic waves, which indicates an oxidation process dependent on the chemical environment on the surface of the electrode. The cathodic scan presented an inverted oxidation peak with an onset partially overlapping with the tail of the cathodic peak for the reduction of the platinum oxide formed initially during the anodic scan. This inverted peak can be observed at a potential close to +0.2V (vs Ag/AgCl at pH 2) and separated 0.4 and 0.8 V from the two other oxidation peaks obtained during the anodic scan and in such conditions that the surface is particularly activated to favour this electrochemical process. The response obtained in the electronic current for the different peaks when GHB concentration and scan rate were changed allows inferring that these are the result of a potential dependent mechanism.

Study of the electro-oxidation of a recreational drug GHB (gamma hydroxybutyric acid) on a platinum catalyst-type electrode through chronoamperometry and spectro-electrochemistry

“…It is also consistent with the low current density observed by cyclic voltammetry [8]. Due to the interaction of GHB on the platinum surface, as can be seen by the partial suppression of UPD of hydrogen by voltammetry, we cannot discard a step of surface diffusion or another diffusion path of GHB towards activated centres of oxidised platinum (with a finite thickness of the diffusion layer).…”

“…This difference with respect the behaviour at high potential seems to suggest adsorption of GHB on the surface of the electrode with an additional positive contribution in the j-t curve at low time. It has been reported previously in a study by cyclic voltammetry [8].…”

“…A first paper on the electro-oxidation of gamma hydroxybutyric acid on a polycrystalline platinum electrode by cyclic voltammetry in acidic medium was recently released [8]. The cyclic voltammograms showed two oxidation peaks, A and B, within the potential range of the double layer region and that of the platinum oxide region ( Figure 1).…”

“…All solutions were prepared with deionized water produced by a Millipore system (Millipore, Maryland, US). GHB sodium salt, was prepared and identified as is described in reference [8].…”

Rapid Drop-Volume Electrochemical Detection of the “Date Rape” Drug Flunitrazepam in Spirits Using a Screen-Printed Sensor in a Dry-Reagent Format

“…All the chemicals were of analytical grade and purchased from Merck (Darmstadt, Germany) or Sigma-Aldrich (St. Louis, MO, USA). Ketamine, flunitrazepam and gamma-hydroxy butyric acid lactone (GBL) were from Sigma-Aldrich; gamma-hydroxybutyric acid (GHB) sodium salt was prepared and characterized as described previously [ 18 ]. Doubly distilled water was used throughout.…”